Azido cyclohexanepentol derivative

ABSTRACT

Cyclohexanepentol derivative i.e. 1L-1-azido-1-deoxy-myoinositol of the formula:   WHICH IS AN INTERMEDIATE PRODUCT FOR THE PREPARATION OF THE KNOWN CORRESPONDING AMINOCYCLITOL.

United States Patent Cier et al.

[ June 3,1975

Ablon; Alain Olesker, Marcoussis, all of France [73] Assignee: Labaz, Paris, France [22] Filed: July 30, 1973 [21] Appl. No.: 383,665

[30] Foreign Application Priority Data Aug, 16, 1972 United Kingdom 38300/72 [52] US. Cl. 260/349 [51] Int. Cl. C07c 117/00 [58] Field of Search 260/349 [56] References Cited UNITED STATES PATENTS 3,496,196 2/1970 Suami et al. 260/349 Primary ExaminerJohn M, Ford Attorney, Agent, or FirmMason, Kolehmainen, Rathburn & Wyss [5 7] ABSTRACT Cyclohexanepentol derivative i.e. lL-l-azido-l-deoxymyo-inositol of the formula:

which is an intermediate product for the preparation of the known corresponding aminocyclitol.

1 Claim, N0 Drawings AZIDO CYCLOHEXANEPENTOL DERIVATIVE The present invention relates to'a novel cyclohexanepentol derivative, namely lL-l-azido-l-deoxy-myoinositol corresponding to the formula:

in which the symbol Ac represents acetyl.

The starting-compound represented by formula Il may be prepared by a series of known operations commencing with the known compound, lL-3,4:5,6-di-0- cyclohexylidene-Z-O-methyll-O-tosyl-chiro-inositol published by GERO et al. in Tetrahedron Letters pp, 591-595 (1966), and corresponding to the formula:

III

wherein the symbol Ts represents a tosyl group, which is heated in an appropriate solvent such as, for example, N,N-dimethylformamide, with an alkaline azide such as sodium azide to give lL-l-azido-l-deoxy- 2,3:4,5-di-O-cyclohexylidene-6-0-methyl-myo-inositol of the formula:

which is hydrolysed, for example, with hydrochloric acid to provide lL-l-azido-l-deoxy-6-0-methyl-myoinositol of the formula:

YOK

This latter compound may then be treated with acetic anhydride in an appropriate solvent such as, for example, pyridine to give lL-2,3,4,5-tetra-O-acetyl-l-azidol-deoxy-6-0-methyl-myo-inositol of the formula:

wherein the symbol Ac represents an acetyl group, which is oxidized with chromic anhydride at roomtemperature and in an appropriate medium such as, for example, acetic acid to provide the starting-compound of formula II.

The novel cyclohexanepentol derivative of the invention constitutes a very useful intermediate compound which may be used, for example, for the preparation of the corresponding aminocyclitol and its salts. The aminocyclitol which may be obtained from the compound of formula I, namely lD-myo-inosamine, is a known compound which is particularly useful owing to the fact that is chemical structure presents marked similarity to the natural diaminocyclitols included in the molecular composition of antibiotics of the hybromycin series.

However, lD-myo-inosamine is not a very stable compound as it detoriates fairly quickly. It cannot, therefore, be easily stored and consequently must be prepared immediately before use.

The azide of formula I, on the other hand, which can be used for the preparation of lD-myo-inosamine is easy to handle, very stable and can be stored for long periods of time which means that it offers the appreciable advantage of being immediately available when required without having to be prepared on every occasion when its use is indicated. Moreover, the presence of the azide group in the compound of formula I confers on this molecule a high degree of reactivity and in particular will enable subsequent reactions to be performed which would otherwise be impossible or at least very difficult.

As stated above, lD-myo-inosamine is a known compound. It was disclosed by G.G. POST in Ph. D. Thesis, University of Wisconsin, 1959. According to the method of preparation described therein, lD-myoinosamine is obtained by catalytic reduction of the phenylhydrazone of lD-myo-inosose, itself prepared by catalytic oxidation of L-inositol. However, the yield in lD-myo-inosamine, obtained by this process is very low being about 9 to 10 Furthermore, the lD-myoinosamine so obtained contains impurities of which the major part is composed of 2L-inosamine which must be separated out by chromatography.

For these reasons, the method for preparing lD-myoinosamine as described in the aforesaid reference presents considerable disadvantages as regards use on the industrial scale since low yields and chromatographic separation are not acceptable at this level. This process is consequently of little practical interest.

As opposed to this, the preparation of lD-myoinosamine by catalytic reduction of the azide of formula I is particularly advantageous on the industrial scale as the yield in lD-myo-inosamine by this method is practically quantitative. Furthermore, the lD-myoinosamine prepared in this way is devoid of impurities which obviates the need for operations of elimination which are so costly when working on the industrial scale.

Because the azide of formula I can be converted to the corresponding aminocyclitol or its salts without any difficulty and with a practically quantitative yield, this aminocyclitol may be prepared from the azide of formula I whenever required.

Thus, owing to the fact that the novel cyclohexanepentol of formula I may be easily and rapidly converted to lD-myo-inosamine, this latter compound may be considered to be available almost as readily as if it could be prepared and stored well in advance of its use.

This is an advantage which the method described in the abovementioned Ph. D. Thesis does not offer.

The following Example illustrates the preparation of the compound of the invention:

EXAMPLE Preparation of 1L-l-azido-l deoxy-myo-inositol a. Preparation of lL-l-azido-l-deoxy-2,3:4,5-di-O- cyclohexylidene-6-0-methyl-myo-inositol (Formula IV) To a solution of 33 g of 1L-3,4:5,6-di-0- cyclohexylidene-Z-O-methyl-l-0-tosyl-chiro-inositol in 220 ml of N ,N-dimethylformamide were added g of sodium azide. The reaction mixture was heated while being stirred at C for about 12 hours and then poured into iced water. The mixture was extracted with chloroform after which the solvent was evaporated out under high vacuum. By this means, 15 g of a sticky brown-coloured product were obtained which were dissolved in a 10/90 ethyl acetate/petroleum ether mixture. The solution. so obtained, was purified by chromatography on a column of silicagel (Davison 100/200) and the solvent was evaporated out.

In this manner, 10 g of lL-l-azido-l-deoxy-2.3:4.5- di-O-cyclohexylidene-6-0-methy1-myo-inosito1 were obtained, melting at 99-10lC, after recrystallization from an ethyl acetate/petroleum ether mixture, which represents a yield of 46% in pure product.

[011 40 (c 1.0, chloroform) b. Preparation of lL-l-azido-1-deoxy-6-0-methy1- myo-inositol (Formula V) In 90 ml of methanol containing 7 m1 of concentrated hydrochloric acid were dissolved 1 l g of lL-l-azido-ldeoxy-2,324,5-di-0-cyclohexylidene-6-0-methyl-myoinositol, prepared as described hereabove. The reaction mixture was heated under reflux at 70C for 3 hours after which the solvent was evaporated out under vacuum. The residue was take up several times with ethanol and benzene and again evaporated to eliminate the solvents and the hydrochloric acid. In this manner, 5.3 g of white crystals of lL-l-azido-l-deoxy-6-0- methyl-myo-inositol were obtained, melting at l77-l79C, after recrystallization from a benzene/ethanol mixture which represents a yield of 81% in pure product.

[ 10 29 (c 1.04, methanol) c. Preparation of lL-2,3,4,5-tetra-O-acetyll -azidol deoxy-6-0-methyl-myo-inositol (Formula IV) In 50 ml of pyridine were dissolved 5.3 g of lL-lazido-1 deoxy-6-0-methyl-myo-inositol, prepared as described hereabove. Through a dropping-funnel was added to this solution, drop-by-drop, a mixture of 21 ml of acetic anhydride and 0.6 ml of concentrated hydrochloric acid. The reaction was conducted for 12 hours then the reaction medium was poured into an iced aqueous solution of sodium bicarbonate while being magnetically stirred. The precipitate so formed was filtered out on a Biichner-funnel and washed with water to neutrality.

In this manner, 8.5 g of 1L-2,3,4,5-tetra-0-acetyllazido-1-deoxy-6-0-methyl-myo-inositol were obtained, melting at l73C, after recrystallization from ethanol, which represents a yield of 91% in pure product.

[01],, 39 (c 1.62, chloroform).

(1. Preparation of lL-2,3,4,5-tetra-0-acetyl-l-azido- 1 deoxy-6-O-formyl-myo-inositol (Formula II).

To a solution of 19 g of chromic anhydride in 400 ml of glacial acetic acid, were added 8.5 g of 1L-2,3,4,5- tetra-O-acetyll -azido- 1 -deoxy-6-0-methyl-myoinositol prepared as described hereabove. The reaction was conducted at room-temperature for 5 or 6 hours. Chloroform was added to the reaction medium which was then gently poured into a iced solution of sodium bicarbonate while being magnetically stirred. The chloroformic layer was decanted out and the aqueous phase was extracted twice with Chloroform. The chloroformic phases were collected, washed with water to neutrality after which the solvent was evapored off under reduced pressure.

In this manner, 7 g of lL-2,3,4,5-tetra-O-acetyl-lazido-l-deoxy-6-0-formyl-myo-inositol were obtained,

melting at l87l90C after recrystallisation from methanol which represents a yield of 79% in pure product.

[0:],{ l3.5 (c 0.82, chloroform).

e. Preparation of 1L-l-azido-l-deoXy-myo-inositol (Formula I) To a solution of ml of anhydrous methanol and 0.2 ml of a normal solution of sodium methanolate, were added 3 g of lL-2,3,4,5-tetra-0-acetyl-l-azido-ldeoxy6-0-formyl-myo-inositol, prepared as described hereabove. The reaction was conducted at roomtemperature for 5 hours after which the solvent was evaporated off under reduced pressure and the residue was taken up in absolute ethanol. The precipitate so formed was filtered out on a Biichner-funnel, washed with a small quantity of absolute ethanol and then allowed to dry in a desiccator.

In this manner, 1.2 g of lL-l-azido-l-deoxy-myoinositol were obtained, melting at 172C, which represents a yield of 76%.

[01],, 6 (c 1.28, methanol) We claim:

1. lL-l-azido-l-deoxy-myo-inositol of the formula: 

1. 1L-L-AZIOD-L-DEOXY-MYO-INOSITOL OF THE FORMULA: 